Problem: Simplify the expression. $ (-z^{6}+4z^{2}-4z) + (-z^{6}-5z^{2}+4z ) $
Explanation: Since we are adding polynomials, we can simply remove the parentheses. $-z^{6}+4z^{2}-4z - z^{6}-5z^{2}+4z$ Identify like terms. $ - { z^6} + \color{#DF0030}{4 z^2} - {4 z} - { z^6} - \color{#DF0030}{5 z^2} + {4 z} $ Combine like terms. $ { ( -1 -1 ) z^6} + \color{#DF0030}{ z^2} + { z} $ Add the coefficients. $-2z^{6}-z^{2}$